Diestock



I. w. NONNEMAN nmsrocx Filed June 10 '1925 :s sheets-sheet 2 I mfiw 54M H mm wag! Patented Get. 4, 1927.

entree, STATES PATENT OFFICE.

WARREN,

Ina w. NONNEMAN,

oirr'o assienon TO II-IE onner; CO PANY; or wan-nan, care, a ccaroanrxon or onto. I I

mns'roox.

' application filed June 10, 1925. Serial No. 86;0 89.

This invention relates to die stocks of the typewherein the chasers occupy fixed positions while in operation, for different sizes of pipe to be cut.

In the operation'of die stocks, the practice heretofore has been to adj net the chasers to the desired size, then to rotate the die stock'by hand until the thread is cut, and

then tofreverse the direction of rotation, spinning the die stock until it is removed from the work. One'of theobjects of the present invention is'to provide means for releasing the chasers from the work after a thread hasbe'en cut. so that the die stock maybe withdrawn merely by an axial movement without necessitating any turning in a direction opposite to that required for. the threading operation. In this connection my invention contemplates the provision of means for enabling the chasers to be readily reset after the die stock'is removed from the work, without necessitating careful manipu lation of the adjusting means- Another object of the present invention is concerned with'the provision of means. for e'nabl-ing'the chasers to be quickly adjusted for different sizes of pipes, and for prevent-x ing the chasers from falling out of position in casethe adjusting device is moved mad-1 vertentlyto the extreme position.

A. further object of my invention is the provision'ot means for clamping the chasers in position and for so holding them that the normal action of the chasers .to move radially outward during the cutting is re= sisted in. pr'oportion'to the force tending to so move them. d An additional: purpose of the present in vention is the provision of a die stock head which is so made that the chipsmay be thrown out of the way during the cutting operation, whereby cloggingof' the tool is prevented. r

The preferred form for carrying out my I. invention is illustrated in the drawings wherein Fig. 1 is a plan view of a die stock embodying my invention; Fig. 2 is a side elevation of the die stock shown in Fig. 1; Fig.2 3 is a transverse section taken on a plane indicated by the line 3 3in Fig. 1; Figs. 4 and 5 are transverse sections taken through the die stock on planes indicated by the lines 1 i and 5 5 respectively in. Fig.

5 a sectionsimilar to that but are adj ustable.

in Fig. 5 but showing the releasing means. in a difierentposition from that illustratedin Fig. 5; Fig. 7 is asectional View takenon the plane indicated by the line 7-7 in.

Fig. 1, and Fig. 8 is a detail. view showing the edge of a portion of the scroll plate and: head. I I have. shown my invention in connection with-a die stock having a frame 10; adja cent one end: of which chasers 11 are positioned, and at the other end of which, guide. bars 12 are adjustably mounted. The frame is illustrated as having an annular web L3. spaced inwardly from the chaser end: thereof, and as having a scroll plate 14 which functions to permit adjustment of the chasers to the desired size of pipe.

The chasers as, indicated are mounted within radial slots within a head 15 which in turn is rigidly attached: as by securing.

' members 16 to the frame. Each chaser may;

have a lug 17 which projects into one of the grooves 18 in the scroll plate. These laterally extending portion 19 for enabling the chasers to be readily slid outwardly from the scroll plateand thereby to be re-t moved from the die stock' whenever desired.

To prevent thechasers from falling out of the die stock during the adjusting operation, I provide means for'limiting the arignla-r movement of the scroll platein: one direction with reference to the frame and I so arrange such means that it may readily be released to permitfurther selective movement of the scroll plate to the extreme position. The preferred arrangement for ac-- complishing this result includes a non-circular pin 20 which is slidably mounted:with.-- in a slot 21. This slot is formed within an extension 22 of the scroll plateand is are ranged to be concentric with the scroll plate. The positionot the 20. within the slot is controlledby the position. of a lever 23 which may be pivotally mounted: at 24 within a lug 25 on. the frame. An arm 26 is shown as being rigidly-mounted upon the pivot pin 24 (Fig. 7) and on that side. of the lug 25 opposite to the lever 23. The arm may be pivotally connected at27 to'a link 28 which in. turn is oneratively senses-ted pin. 20.-

The position of the pivot pin 24 upon the frame is such that when the lever 23 is in the position shown in Fig. 5, then the lugs 17 on the respective chasers are near but are spaced from the lateral groove portion 19. Moreover the length of the arm 26 and link 28 is such that when the lever 23 is in the position shown in Fig. 5, then the pin 20 is at the end of the slot 21. This limits the angular movement of the scroll plate 1n a'direction to open the chasers, and at the same time prevents the chasers from being withdrawn from the die stock.

To permit the withdrawal of the chasers from the die stock, the lever 23 is swung about the pivotal connection until. the arm 26 engages a stop pin 31. This moves the pin 20 along the slot and away from the shoulder or end 30. Thereafter, the scroll plate may again be moved to bring the end 30 against the pin 20. hen this is done, then the lugs 17 on the respective chasers are adjacent the lateral grooves 19. The chasers may then he slid radially out of the slots in the head in the usual manner.

To look the chasers in adjusted position, I have shown a threaded sleeve which engages a threadedextension 86 on the pin 20. A bar 38 extends through the sleeve 35 and may be employed for turning it to lock the arm 28 to the scroll plate.

The normal tendency of the chasers during the cutting operation is to recede from the work and consequently to rotate the scroll plate with reference to the frame. To overcome this I have shown that portion of the scroll plate adjacent the slot 21 as being tapered as at 40. The function of the tapered surface 4-0 on the scroll plate is to bind the plate against the retaining washers 41 and 42, whenever the plate is rotated in a direction which would tend to open the chasers. Accordingly after the clamp lever 38 is moved to lock the scroll plate, then any force during the cutting operation which tends to rotate the scroll plate will increase the locking power of the clamp.

The locking device heretofore described is advantageous in that after an adjustment of the chasers is once made, then the actuation of the lever 23 will operate to shift the chasers simultaneously away from the work soas to permit the withdrawal of the die stock from the work'without requiring it to be rotated in a direction opposite to that employed for the threading operation. This is readily apparent from inspection of Fig. 5 and Fig. 6. In Fig. 5, for example, the lever 23 is in the'locked position while in F ig..6, the lever is in the-unlocked position. Moreover, in Fig. 5, the lugs 17 are shown as being closer the axis of the die stock than as shown in Fig. 6. Accordingly, if the lever 38 is maintained inlocked position, and if the lever 23 is shifted while the clamp is so locked, then the scroll plate 1.4: is necessarily rotated about theframe in a direction to cause the withdrawal of the chasers from the work.

After the die stock is removed from the work, then the operator need only throw the shift lever 23 back to the original position:

as shown in Fig. 5, whereupon the chasers are automatically reset to the original position. The lever 23 is automatically locked in the clamping position by reason of the fact that the axis of the pivotal connections helical rib 56 thereon to control radial move ment of the bars whenever the cam is rotated. A nut 57 threaded onto the frame in the desired position.

Considerable difiiculty has heretofore been experienced in connection with the operation of die stocks in that chips are apt to lodge between the chasers and the'cutting head and to clog the chaser teeth. Toovercome this I provide recesses 60 between the chasers and within the head 15. The lug 61 in which the chasers are mounted may have one edge at 62 chamfered to permit the chips to fall into the recesses during the cutting operation.

To operate the die stock I have shown ma 7 be em loved for lockin r the cam Jlate .3 P a l 90 sockets 63 for receiving handles in the usual way. A die stock made in accordance with my invention is advantageous in that a large number of pipes of one size may be threaded in a materially reduced period of time by reason of the fact that the die stock can be quickly withdrawn after the thread is out, while the chasers can be readily reset to the previous position to perform the cutting operation on the next pipe, without danger of disturbing the adjustment. A further advantage of my invention is the fact that whenever the chasers are adjusted for a different size of pipe, there is no dangerof a1- lowing them to fall out of the die stock. This enables the operator to adjust the chasers without requiring his attention to be directed to the position of the scroll plate so H 1 as to prevent madvertent movement thereof too far in one direction. 7

A further advantage of my invention is the fact that the scroll plate when once locked by the clamping means is held tighter as theforce which tends to open the plate is increased.

Having thus described my invention, I claim I 1. In a die stock, the combination with a frame member, chasers mounted therein, a

, same with the adjustable pin, said clamping member having, an extreme position where it releases the chasers and the slot be ng Long enough to allow the member to be moved to release the chasers only when the rock arm IS in ltSBXtIBIIlQ non-clamping position, and the, clamping nut loosened.

2'. In a die stock, the combination with a Frame, of a plurality of chasers carried thereby, a plate rotatably mounted on the frame and operatively connected to the chasers, said plate being normally limited in its angular movement to prevent withdrawal of the chasers from the frame, and a releasing device carried by the frame for increasing the permissible angular movement of the plate to allow withdrawal of the chasers from the frame, said device also functioning to lock the plate to the frame.

3. In a die stock, the combination with a frame, of a plurality of chasers carried thereby, a cam plate having a pluralityof cam slots therein for effecting simultaneous operation of the chasers, and each of said slots having a laterally extending portion to permit removal of the chasers from the die stock, a member adapted to engage the cam plate in various positions and adapted to be locked thereto or unlocked for normally limiting the angular movement thereof, to prevent withdrawal of the chasers through the lateral extending portion of the. cam slots, and a lever pivotally mounted on the frame for shifting said member when unlocked to permit further rotation of the cam plate whereby the chasers may be removed from said frame 4. In a die stock, the combination with a frame and a plurality of chasers movably mounted thereon and near one end thereof, said frame having pockets between the chas-' ers closed at the ends by the chaser housings, at the outer edge by the frame wall and at the bottom by an annular portion of the frame, each pocket being so located that with reference to the direction of rotation it is in front of the corresponding chaser to receive cuttings from the work and to prevent clogging during the cutting operation.

5. In a die stock, thecombinationwith a frame, of a a plurality of chasers carried thereby, a cam plate rotatably mounted on the frame for controlling the position of the chasers wi h reference to the frame, means for clamping the plate to the .frame and for holding the chasers in adjusted position, said means including a tapered bearing surface on the plate whereby the force tending creased as working stresses which tend to openthe chasers are increased.

6. In rame. thereby, means for clamping the'chasers to the frame in an "adjusted. position, .said means includin a movable member having a connection with; the chasers'to positively to, cri p the chasers to; the; frame is inmove themin and out and a clamping mem- 2 her active on the; movable member, one of said members having tapered surfaces coacting withthe the clamping force is increased as the working stresses whi'c'h' tend to open the chasers are increased. 7

other member, so'arranged' that g a die stock, the" combination with a of a plurality of chasers carried 1 7. In a die stock, the combination with a frame, of a plurality of chasers carried thereby, a cam plate rotatably mounted upon the frame for controlling the position of the chasers, mounted upon the frame for locking the plate to the frame, said means also including a ta 'ered' bearing surface on the plate, said bearing surface being so inclined that the force which tends to clamp the plate is in-' means including a link pivotally creased as the working stresses which tend,

to open the chasers are increased.

8. In a die stock, the combination with a frame, of a plurality of chasers carried thereby, a cam plate rotatably mounted upon the frame and operatively connected with the chasers for simultaneously adjusting them with referenceto the frame,,said plate having a slot therein and having a tapered portion on each side of the slot, a pin projecting through the slot, means for clamping the pin to the plate, said means engaging the tapered bearing portion,and mechanism operatively connecting said means with the frame.

'9. In a die stock, the combination with a frame, of a plurality of chasers operatively carried thereby, a cam plate rotatably a frame, of a plurality of chasers carried thereby, a cam plate for simultaneously moving the chasers with reference to the frame, said cam plate having a] projecting portion provided with an arcuate slot, a pin adapted to be in the slot, a lever pivotally mounted upon the frame, and a link operatively connecting Hit) clamped in adjusted, position I the lever with saidpin, said lever and link functioning when in one position to lock the plate to the framewhen in another position to release the chasers.-

11.-In a die stock, the combination with a frame of a plurality of. chasers carried thereby, a cam plate mounted on the frame and operatively connected with the chasers -for moving all of them simultaneously with reference to the cam, said plate having a plurality of cam slots therein and each chaser having a plug projecting into one of the slots and each of said slots having a laterally extending portion adjacent one end to permit removal of the chasers from the die the frame, and a link operatively connecting 20 the lever with said pin, whereby the cam plate is prevented from being rotated to bring the lugs opposite the laterallyextending portion but may be so rotated when the pin is released to permit further rotation of the cam plate.

In testimony whereof, I hereunto afiix my signature.

IRA NONNEMAN. 

